package com.booksystem.service.impl;

import com.booksystem.common.RestResult;
import com.booksystem.dto.ProductRankQuery;
import com.booksystem.dto.ReportQuery;
import com.booksystem.entity.OrderInfoDO;
import com.booksystem.exception.BusinessException;
import com.booksystem.mapper.OrderInfoMapper;
import com.booksystem.service.ReportService;
import com.booksystem.vo.ProductRankVO;
import com.booksystem.vo.SalesReportVO;
import com.booksystem.vo.UserBehaviorAnalysisVO;
import java.math.BigDecimal;
import java.time.LocalDateTime;
import java.util.*;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * <p>
 *   数据统计分析服务实现类
 * </p>
 * @author 段伟豪
 */
@Slf4j
@Service
public class ReportServiceImpl implements ReportService {

    @Autowired
    private OrderInfoMapper orderInfoMapper;

    @Override
    public RestResult<SalesReportVO> generateSalesReport(ReportQuery query) {
        // 校验输入的时间范围是否合法
        if (!validateTimeRange(query.getStartTime(), query.getEndTime())) {
            return new RestResult<>(ResultCodeConstant.CODE_000001, ResultCodeConstant.CODE_000001_MSG);
        }

        try {
            SalesReportVO reportVO = new SalesReportVO();

            // 查询指定时间段内的订单数据
            List<OrderInfoDO> orders = orderInfoMapper.selectList(null);
            // 这里可以根据实际需要进行筛选和聚合计算

            // 示例逻辑：假设我们只做了简单的汇总
            int orderCount = orders.size();
            BigDecimal totalAmount = orders.stream()
                    .map(OrderInfoDO::getTotalAmount)
                    .reduce(BigDecimal.ZERO, BigDecimal::add);

            reportVO.setOrderCount(orderCount);
            reportVO.setTotalAmount(totalAmount);
            reportVO.setAverageAmount(totalAmount.divide(new BigDecimal(orderCount), 2, BigDecimal.ROUND_HALF_UP));

            return new RestResult<>(ResultCodeConstant.CODE_000000, ResultCodeConstant.CODE_000000_MSG, reportVO);
        } catch (Exception e) {
            log.error("生成销售报表失败", e);
            throw new BusinessException(ResultCodeConstant.CODE_000002, ResultCodeConstant.CODE_000002_MSG);
        }
    }

    @Override
    public RestResult<UserBehaviorAnalysisVO> analyzeUserBehavior(ReportQuery query) {
        // 校验输入的时间范围是否合法
        if (!validateTimeRange(query.getStartTime(), query.getEndTime())) {
            return new RestResult<>(ResultCodeConstant.CODE_000001, ResultCodeConstant.CODE_000001_MSG);
        }

        try {
            UserBehaviorAnalysisVO behaviorVO = new UserBehaviorAnalysisVO();

            // 假设这里做一些模拟的数据分析
            Map<String, Object> analysisData = new HashMap<>();
            analysisData.put("visitCount", 1000); // 访问次数
            analysisData.put("orderCount", 500);   // 下单次数
            analysisData.put("favoriteCount", 300); // 收藏次数

            behaviorVO.setAnalysisData(analysisData);

            return new RestResult<>(ResultCodeConstant.CODE_000000, ResultCodeConstant.CODE_000000_MSG, behaviorVO);
        } catch (Exception e) {
            log.error("分析用户行为模式失败", e);
            throw new BusinessException(ResultCodeConstant.CODE_000003, ResultCodeConstant.CODE_000003_MSG);
        }
    }

    @Override
    public RestResult<List<ProductRankVO>> getProductRank(ProductRankQuery query) {
        // 校验输入的时间范围是否合法
        if (!validateTimeRange(query.getStartTime(), query.getEndTime())) {
            return new RestResult<>(ResultCodeConstant.CODE_000001, ResultCodeConstant.CODE_000001_MSG);
        }

        try {
            List<ProductRankVO> rankList = new ArrayList<>();

            // 实际开发中应从数据库查询并按销量排序
            for (int i = 0; i < query.getLimitCount(); i++) {
                ProductRankVO vo = new ProductRankVO();
                vo.setProductName("商品" + i);
                vo.setSalesQuantity(i * 100);
                rankList.add(vo);
            }

            return new RestResult<>(ResultCodeConstant.CODE_000000, ResultCodeConstant.CODE_000000_MSG, rankList);
        } catch (Exception e) {
            log.error("获取商品热销排行失败", e);
            throw new BusinessException(ResultCodeConstant.CODE_000004, ResultCodeConstant.CODE_000004_MSG);
        }
    }

    /**
     * 校验时间范围合法性
     * @param start 开始时间
     * @param end 结束时间
     * @return 是否合法
     */
    private boolean validateTimeRange(LocalDateTime start, LocalDateTime end) {
        if (start == null || end == null) {
            return false;
        }
        return !start.isAfter(end);
    }
}